High inpatient-opioid consumption predicts extended length of hospital stay in patients undergoing spinal fusion for adolescent idiopathic scoliosis.

Objectives: Opioids are common medications used following spine surgery. However, few studies have assessed the impact of increased inpatient-opioid consumption on outcomes following posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS). The aim of this study was to determine the impact of increased inpatient-opioid consumption on hospital length of stay (LOS) following PSF for AIS.

Methods: A retrospective cohort study was performed using the Premier Healthcare Database (2016-2017). Adolescent patients (11-17 years old) who underwent PSF for AIS, identified using ICD-10-CM coding, were stratified by inpatient MME (morphine milligram equivalent) consumption into Low (< 25th percentile for the cohort), Medium (25-75th percentile), and High (> 75th percentile) cohorts. Demographics, comorbidities, intraoperative procedures, perioperative adverse events (AEs), length of hospital stay (LOS), non-routine discharge rates, cost of admission, and 30-day readmission rates were assessed. A logistic multivariate regression analysis was performed to determine the association between inpatient MME consumption and extended LOS.

Results: Of the 1042 study patients, 260 (24.9%) had Low-MME consumption, 523 (50.2%) had Medium-MME consumption, and 259 (24.9%) had High-MME consumption. A greater proportion of patients in the High cohort identified as non-Hispanic white (Low: 46.5% vs Medium: 61.4% vs High: 65.3%, p < 0.001), while the proportion of patients reporting any comorbidity did not vary across the cohorts (p = 0.940). The number of post-operative AEs experienced also did not vary across the cohorts (p = 0.629). A greater proportion of patients in the High cohort had an extended LOS (Low: 6.5% vs Medium: 8.6% vs High: 19.7%, p < 0.001), while a greater proportion of patients in the Low cohort had an increased cost of admission (Low: 33.1% vs Medium: 20.3% vs High: 26.6%, p < 0.001). The High cohort had increased 30-day readmission rates relative to the Low and Medium cohorts (Low: 0.8% vs Medium: 0.2% vs High: 1.5%, p = 0.049). Non-routine discharge rates did not vary among the cohorts (p = 0.441). On multivariate analysis, High-MME consumption was significantly associated with extended LOS, while Medium-MME consumption was not [Medium: aOR: 1.48, CI (0.83, 2.74), p = 0.193; High: aOR: 4.43, CI (2.47, 8.31), p < 0.001].

Conclusions: Our study showed that high post-operative-MME consumption was significantly associated with extended LOS in patients undergoing PSF for AIS. In light of these findings, changes to existing protocols that decrease the reliance on opioids for post-operative analgesia are merited to improve patient outcomes and reduce health-care expenditures.